There are numerous procedures, rules, laws, and other details that need to be accounted for in any time management system. For example, each company has a different fiscal year or calendar year requirement for time management, different countries have different laws for vacation and sick time, vacation and sick time may accrue differently depending on the company or country, new laws may create new requirements, etc. It is not possible to do all of these tasks manually but human resource administrators still must configure these tasks manually to be run in batch mode on a regular basis. To prepare these tasks manually, however, is incredibly complicated and leads to various issues such as data inconsistency, unpredictable run times, unfair distribution of resources in a data center, inability to track progress of tasks, and an inability to recover efficiently from crashes.